In automotive systems, lubrication is essential. When the engine is operating, the oil is circulated. When the engine is turned off, most of the oil collects in a sump provided in the engine and the oil level rises, normally, to a level indicating that there is sufficient oil in the engine sump. When the oil level is at a sufficient height, the engine when started, will be properly lubricated. At that time during operation, the oil is again circulated through the engine, and therefore most of it is withdrawn from the sump.
Various devices and systems have been used or proposed for determining the level of the engine oil for proper circulation when the engine is turned off, in order to make sure that there is enough oil for proper circulation of lubrication when the engine is again turned on. A primitive indication may be obtained by a dipstick, but the use of a dipstick requires one to raise the hood, pull the dipstick out, wipe it off, put it back in, and pull it out again. Prior-art devices and system proposed to replace the dipstick have been either very expensive or have not been able to obtain the desired results.
An object of this invention is to provide an inexpensive yet accurate system for determining whether (after a predetermined time following turning the engine off), there is the proper amount of oil in the sump; that is, whether the oil has risen to a desired height or level.
Another object of the invention is to supply the engine sump with additional oil when the sensor indicates that there is an insufficient amount of oil in the sump at that time.
Another object of the invention is to warn the driver or other engine operator when the reserve oil supply reservoir for adding oil to the engine sump needs additional oil or else replacement of reserve oil in the reservoir.